<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "xhtml1-transitional.dtd">
<!-- saved from url=(0013)about:internet -->
<?xml-stylesheet type="text/xsl" href="mathml.xsl"?><html xmlns="http://www.w3.org/1999/xhtml" xmlns:pref="http://www.w3.org/2002/Math/preference" xmlns:xlink="http://www.w3.org/1999/xlink" pref:renderer="mathplayer-dl">
  <head>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
    <style xmlns="" type="text/css">
    /* This style sets a margin around the entire page */
        html, body {
            margin: 10px;
        }

        p {
            font: normal 16px verdana, sans-serif;
            margin: 0;
            padding-bottom:12px;
        }

        h1 {
            font: bold 25px verdana, sans-serif;
            margin-top: 0;
            margin-bottom: 3px;
            padding-top: 0;
            padding-bottom: 0;
        }

        h2 {
            font: bold 19px verdana, sans-serif;
            margin-top: 28px;
            margin-bottom: 3px;
            padding-top: 0; 
            padding-bottom: 0;
        }

        h3 {
            font: bold 19px verdana, sans-serif !important;
            margin-top: 28px;
            margin-bottom: 3px;
            padding-top: 0;
            padding-bottom: 0;
        }

        li {
            font: normal 16px verdana, sans-serif;
            margin-top: 0;
            margin-bottom: 18px;
            padding-top: 0;
            padding-bottom: 0;
        }

        .pdparam {
            font: italic 16px verdana, sans-serif;
        }
		
		.term {
			font: italic 16px verdana, sans-serif;
			font-weight: normal;
		}	
		
		.type {
			font: normal 16px verdana, sans-serif !important;
		}			
		
		.parameter { 
			font-style: italic; 
			}

        a:link, a:visited {
            color: blue;
            text-decoration: none;
            font: normal 16px;
        }

        a:hover {
            background-color: #FFFF99;
            font: normal 16px;
        }

        div.funcsynopsis {
            text-align: left;
            background-color: #e6e6e6;
            font: normal 16px verdana, sans-serif;
			padding-top: 10px;
			padding-bottom: 10px;
        }

        div.funcsynopsis table {
            border-collapse: separate;
            font: normal 16px verdana, sans-serif;
        }

        div.funcsynopsis td {
            background-color: #e6e6e6;
            border: 0 solid #000;
            padding: 1px;
            font: normal 16px verdana, sans-serif;
        }

        div.refsect1 {
            font-family: verdana, sans-serif;
            font-size: 16px;
        }

        code.constant {
            font: normal 16px courier new, monospace !important;
        }
		
		span.errorname {
            font: normal 16px verdana, sans-serif !important;
        }

        code.function {
            font: bold 16px verdana, sans-serif !important;
        }
		
        b.fsfunc {
            font: bold 16px verdana, sans-serif !important;
        }
		
        code.varname {
            font: italic 16px verdana, sans-serif;
        }

        code.replaceable {
            font: italic 16px courier new, monospace;
        }

        code.funcdef {
            font: normal 16px verdana, sans-serif !important;
        }

        .citerefentry {
            font: normal 16px verdana, sans-serif !important;
        }

        .parameter {
            font-style: italic;
        }

        code.fsfunc {
            font: normal 16px verdana, sans-serif !important;
        }

        /* PARAMETER: This style controls spacing between the terms in Parameter section */
        dt {
            margin-top: 15px;
        }

        /* TABLES: These styles apply to all tables OTHER than the Synopsis and Example tables */
        div.refsect1 table {
            width: 100%;
			margin-top: 10px;
            background-color: #FFF;
			border-collapse: collapse;
			border-color: #000;
            border-width: 1px;
			font: normal 16px verdana, sans-serif;
        }
		
        div.refsect1 th {
			border-collapse: collapse;
			border-color: #000;
            border-width: 1px;
            font: bold 16px verdana, sans-serif;
        }
		
        div.refsect1 td {
            background-color: #FFF;
            padding: 5px;
            vertical-align: text-top;
			border-collapse: collapse;
			border-color: #000;
            border-width: 1px;
            font: normal 16px verdana, sans-serif;
        }
		
		  div.refsect1 p{
            font: normal 16px verdana, sans-serif;
            margin-top: 8px;
            margin-bottom: 8px;
            padding-top: 0;
            padding-bottom: 0;
        }
		

        /* EXAMPLE: These styles apply only to the Example section */
        div.refsect2 {
            font: normal 16px courier new, monospace !important;
        }

        div.refsect2 table {
            margin-top: 0;
            background-color: #e6e6e6;
            width: 100%;
            border: 0 solid #000;
            padding: 2px;
            font: normal 16px courier new, monospace !important;
        }

        div.refsect2 td {
            background-color: #e6e6e6;
            font: normal 16px courier new, monospace !important;
			white-space:pre;
        }

        /* COPYRIGHT: This style formats the text of the copyright statement at the bottom of the page */
        div.refsect3 {
            font: normal 11px verdana, sans-serif;
            margin-top: 50px;
            margin-bottom: 20px;
            padding-top: 0;
            padding-bottom: 0;
        }
					
</style>
    <title>clCreateContextFromType</title>
    <meta name="generator" content="DocBook XSL Stylesheets V1.79.1" />
    <meta name="keywords" content="         &#10;                clCreateContextFromType&#10;            " />
  </head>
  <body>
    <div class="refentry">
      <a id="idm1"></a>
      <div class="titlepage"></div>
      <div xmlns="" class="refnamediv">
        <a xmlns="http://www.w3.org/1999/xhtml" id="clCreateContextFromType"></a>
        <h1>              
            clCreateContextFromType 
        </h1>
        <p>          
            Create an OpenCL context from a device type that identifies the specific device(s) to use.
        </p>
      </div>
      <div class="refsynopsisdiv">
        <h2></h2>
        <div class="funcsynopsis">
          <table xmlns="" border="0" summary="Function synopsis" cellspacing="0" cellpadding="0">
            <tr valign="bottom">
              <td>
                <code xmlns="http://www.w3.org/1999/xhtml" class="funcdef">

                    cl_context

                    <strong class="fsfunc">      
                        clCreateContextFromType
                    </strong>
                (</code>
                <td><a xmlns="http://www.w3.org/1999/xhtml" class="link" href="enums.html#cl_context_properties" target="_top">cl_context_properties</a>
					 <var xmlns="http://www.w3.org/1999/xhtml" class="pdparam"> *properties</var>, </td>
              </td>
            </tr>
            <tr valign="top">
              <td> </td>
              <td><a xmlns="http://www.w3.org/1999/xhtml" class="link" href="enums.html#cl_device_type" target="_top">cl_device_type</a> 
					 <var xmlns="http://www.w3.org/1999/xhtml" class="pdparam">device_type</var>, </td>
            </tr>
            <tr valign="top">
              <td> </td>
              <td><a xmlns="http://www.w3.org/1999/xhtml" class="link" href="scalarDataTypes.html" target="_top">void</a> 
					 <var xmlns="http://www.w3.org/1999/xhtml" class="pdparam">(*pfn_notify)
						(const <a class="link" href="scalarDataTypes.html" target="_top">char</a> *errinfo</var>, </td>
            </tr>
            <tr valign="top">
              <td> </td>
              <td>const <a xmlns="http://www.w3.org/1999/xhtml" class="link" href="scalarDataTypes.html" target="_top">void</a> 
		  			 <var xmlns="http://www.w3.org/1999/xhtml" class="pdparam">*private_info</var>, </td>
            </tr>
            <tr valign="top">
              <td> </td>
              <td><a xmlns="http://www.w3.org/1999/xhtml" class="link" href="scalarDataTypes.html" target="_top">size_t</a> 
					 <var xmlns="http://www.w3.org/1999/xhtml" class="pdparam">cb</var>, </td>
            </tr>
            <tr valign="top">
              <td> </td>
              <td><a xmlns="http://www.w3.org/1999/xhtml" class="link" href="scalarDataTypes.html" target="_top">void</a>
					 <var xmlns="http://www.w3.org/1999/xhtml" class="pdparam">*user_data)</var>, </td>
            </tr>
            <tr valign="top">
              <td> </td>
              <td><a xmlns="http://www.w3.org/1999/xhtml" class="link" href="scalarDataTypes.html" target="_top">void</a>
					 <var xmlns="http://www.w3.org/1999/xhtml" class="pdparam">*user_data</var>, </td>
            </tr>
            <tr valign="top">
              <td> </td>
              <td><a xmlns="http://www.w3.org/1999/xhtml" class="link" href="scalarDataTypes.html" target="_top">cl_int</a>
					 <var xmlns="http://www.w3.org/1999/xhtml" class="pdparam">*errcode_ret</var><code>)</code></td>
            </tr>
          </table>
        </div>
      </div>
      <div class="refsect1">
        <a id="parameters"></a>
        <h2>Parameters</h2>
        <div class="variablelist">
          <dl class="variablelist">
            <dt>
              <span class="term">properties</span>
            </dt>
            <dd>
              <p>
                    Specifies a list of context property names and their corresponding values. Each property name is immediately followed by the corresponding desired value. The list is terminated with 0. <code class="varname">properties</code> can be NULL in which case the platform that is selected is implementation-defined. The list of supported properties is described in the table below. 
                </p>
              <div class="informaltable">
                <table class="informaltable" border="1">
                  <colgroup>
                    <col align="left" class="col1" />
                    <col align="left" class="col2" />
                    <col align="left" class="col3" />
                  </colgroup>
                  <thead>
                    <tr>
                      <th align="left">cl_context_properties enum</th>
                      <th align="left">Property value</th>
                      <th align="left">Description</th>
                    </tr>
                  </thead>
                  <tbody>
                    <tr>
                      <td align="left">
                        <code class="constant">CL_CONTEXT_PLATFORM</code>
                      </td>
                      <td align="left">cl_platform_id</td>
                      <td align="left">Specifies the platform to use.</td>
                    </tr>
                  </tbody>
                </table>
              </div>
            </dd>
            <dt>
              <span class="term">device_type</span>
            </dt>
            <dd>
              <p>
                    A bit-field that identifies the type of device and is described in the table below. 
                </p>
              <div class="informaltable">
                <table class="informaltable" border="1">
                  <colgroup>
                    <col align="left" class="col1" />
                    <col align="left" class="col2" />
                  </colgroup>
                  <thead>
                    <tr>
                      <th align="left">cl_device_type</th>
                      <th align="left">Description</th>
                    </tr>
                  </thead>
                  <tbody>
                    <tr>
                      <td align="left">
                        <code class="constant">CL_DEVICE_TYPE_CPU</code>
                      </td>
                      <td align="left">An OpenCL device that is the host processor. The host
processor runs the OpenCL implementations and is a
single or multi-core CPU.</td>
                    </tr>
                    <tr>
                      <td align="left">
                        <code class="constant">CL_DEVICE_TYPE_GPU</code>
                      </td>
                      <td align="left">An OpenCL device that is a GPU. By this we mean that
the device can also be used to accelerate a 3D API such
as OpenGL or DirectX.</td>
                    </tr>
                    <tr>
                      <td align="left">
                        <code class="constant">CL_DEVICE_TYPE_ACCELERATOR</code>
                      </td>
                      <td align="left">Dedicated OpenCL accelerators (for example the IBM
CELL Blade). These devices communicate with the host
processor using a peripheral interconnect such as PCIe.</td>
                    </tr>
                    <tr>
                      <td align="left">
                        <code class="constant">CL_DEVICE_TYPE_DEFAULT</code>
                      </td>
                      <td align="left">The default OpenCL device in the system.</td>
                    </tr>
                    <tr>
                      <td align="left">
                        <code class="constant">CL_DEVICE_TYPE_ALL</code>
                      </td>
                      <td align="left">All OpenCL devices available in the system.</td>
                    </tr>
                  </tbody>
                </table>
              </div>
            </dd>
            <dt>
              <span class="term">
                <code class="varname">pfn_notify</code>
              </span>
            </dt>
            <dd>
              <p>
                    A callback function that can be registered by the application. This callback function will be used by the OpenCL implementation to report information on errors that occur in this context. This callback function may be called asynchronously by the OpenCL implementation.
It is the application's responsibility to ensure that the callback function is thread-safe. If <code class="varname">pfn_notify</code> is NULL, no callback function is registered. The parameters to this callback function are:
                </p>
              <p><code class="varname">errinfo</code> is a pointer to an error string.</p>
              <p><code class="varname">private_info</code> and <code class="varname">cb</code> represent a pointer to binary data that is returned by the OpenCL implementation that can be used to log additional information helpful in debugging the error.</p>
              <p><code class="varname">user_data</code> is a pointer to user supplied data.</p>
            </dd>
            <dt>
              <span class="term">
                <code class="varname">user_data</code>
              </span>
            </dt>
            <dd>
              <p>
                    Passed as the <code class="varname">user_data</code> argument when <code class="varname">pfn_notify</code> is called. user_data can be NULL.
                </p>
            </dd>
            <dt>
              <span class="term">
                    <code class="varname"> 
                        errcode_ret
                    </code>
                </span>
            </dt>
            <dd>
              <p> 
                        Return an appropriate error code. If errcode_ret is NULL, no error code is returned.
                    </p>
            </dd>
          </dl>
        </div>
      </div>
      <div class="refsect1">
        <a id="notes"></a>
        <h2>Notes</h2>
        <p>
            <code class="function">
                clCreateContextFromType
            </code>

            may return all or a subset of the actual physical devices present in the platform and that match <code class="varname">device_type</code>.
        </p>
        <p>
            <code class="function">clCreateContextFromType</code> and <a class="citerefentry" href="clCreateContext.html"><span class="citerefentry"><span class="refentrytitle">clCreateContext</span></span></a> perform an implicit retain. This is very helpful for 3rd party libraries, which typically get a context passed to them by the application.
However, it is possible that the application may delete the context without informing the library.
Allowing functions to attach to (i.e. retain) and release a context solves the problem of a context
being used by a library no longer being valid.
        </p>
      </div>
      <div class="refsect1">
        <a id="errors"></a>
        <h2>Errors</h2>
        <p>
            <code class="function">clCreateContextFromType</code> returns a valid non-zero context and <code class="varname">errcode_ret</code> is set to <span class="errorname">CL_SUCCESS</span> if the context is created successfully. Otherwise, it returns a NULL value with the following error vlaues returned in <code class="varname">errcode_ret</code>:
        </p>
        <div class="itemizedlist">
          <ul class="itemizedlist" style="list-style-type: disc; ">
            <li class="listitem" style="list-style-type: disc"><span class="errorname">CL_INVALID_PLATFORM</span> if <code class="varname">properties</code> is NULL and no platform could be selected or if platform value specified in <code class="varname">properties</code> is not a valid platform.
            </li>
            <li class="listitem" style="list-style-type: disc"><span class="errorname">CL_INVALID_VALUE</span> if context property name in <code class="varname">properties</code> is not a supported property name, or if <code class="varname">pfn_notify</code> is NULL but user_data is not NULL. 
            </li>
            <li class="listitem" style="list-style-type: disc"><span class="errorname">CL_INVALID_VALUE</span> if <code class="varname">pfn_notify</code> is NULL but <code class="varname">user_data</code> is not NULL.
            </li>
            <li class="listitem" style="list-style-type: disc"><span class="errorname">CL_DEVICE_NOT_AVAILABLE</span> if no devices that match <code class="varname">device_type</code> are currently available.
            </li>
            <li class="listitem" style="list-style-type: disc"><span class="errorname">CL_DEVICE_NOT_FOUND</span> if no devices that match <code class="varname">device_type</code> were found.
            </li>
            <li class="listitem" style="list-style-type: disc"><span class="errorname">CL_OUT_OF_HOST_MEMORY</span> if there is a failure to allocate resources required by the OpenCL implementation on the host.
            </li>
            <li class="listitem" style="list-style-type: disc"><span class="errorname">CL_INVALID_DEVICE_TYPE</span> if <code class="varname">device_type</code> is not a valid value.
            </li>
          </ul>
        </div>
      </div>
      <div class="refsect2">
        <a id="example1"></a>
        <h3>
            Example
        </h3>
        <div class="informaltable">
          <table class="informaltable" border="0">
            <colgroup>
              <col align="left" class="col1" />
            </colgroup>
            <tbody>
              <tr>
                <td align="left">Example goes here - it will be set in "code" type with white space preserved.</td>
              </tr>
            </tbody>
          </table>
        </div>
      </div>
      <div class="refsect1">
        <a id="specification"></a>
        <h2>Specification</h2>
        <p>
            <img src="pdficon_small1.gif" />
							
            <a href="http://www.khronos.org/registry/cl/specs/opencl-1.0.pdf#page=42" target="OpenCL Spec">OpenCL Specification</a>
        </p>
      </div>
      <div class="refsect1">
        <a id="seealso"></a>
        <h2>Also see</h2>
        <p>
<a class="citerefentry" href="clCreateContext.html"><span class="citerefentry"><span class="refentrytitle">clCreateContext</span></span></a>,   <a class="citerefentry" href="clGetContextInfo.html"><span class="citerefentry"><span class="refentrytitle">clGetContextInfo</span></span></a>,  <a class="citerefentry" href="clReleaseContext.html"><span class="citerefentry"><span class="refentrytitle">clReleaseContext</span></span></a>, 	 <a class="citerefentry" href="clRetainContext.html"><span class="citerefentry"><span class="refentrytitle">clRetainContext</span></span></a>, 	
<a class="citerefentry" href="clGetContextInfo.html"><span class="citerefentry"><span class="refentrytitle">clGetContextInfo</span></span></a>	
        </p>
      </div>
      <div xmlns="" class="refsect3" lang="en" xml:lang="en"><a xmlns="http://www.w3.org/1999/xhtml" id="Copyright"></a><h4 xmlns="http://www.w3.org/1999/xhtml"></h4><img xmlns="http://www.w3.org/1999/xhtml" src="KhronosLogo.jpg" /><p xmlns="http://www.w3.org/1999/xhtml"></p>Copyright © 2007-2009 The Khronos Group Inc. 
Permission is hereby granted, free of charge, to any person obtaining a
copy of this software and/or associated documentation files (the
"Materials"), to deal in the Materials without restriction, including
without limitation the rights to use, copy, modify, merge, publish,
distribute, sublicense, and/or sell copies of the Materials, and to
permit persons to whom the Materials are furnished to do so, subject to
the condition that this copyright notice and permission notice shall be included
in all copies or substantial portions of the Materials. 
</div>
    </div>
  </body>
</html>
